Documents for Eric Trump’s trip this week to Dublin show that $4,029.85 was spent on limousines for his visit and $11,261 to cover the hotel costs of the Secret Service agents who protect him.

These purchase orders do not include airfare costs for Secret Service agents who traditionally conduct advance trips to the location in preparation for visits by protectees. It also does not include the cost of the salaries paid to the agents who protect members of the president’s family.

The Trump Organization did not respond to a request for comment.

Eric Trump’s trip to the United Kingdom is his fifth international trip since the start of 2017. He went to Uruguay and the Dominican Republic on his own and accompanied his brother Donald Trump Jr. on his trips to Dubai and Vancouver, Canada.

The trips by the Trump sons are to promote Trump-branded properties in those countries. According to an analysis by the Economist magazine, the Trump Organization’s international deals account for less than 10 percent of the company’s value.

“The Trump family’s frequent travel to international destinations purely to promote the Trump family business is burning through taxpayer dollars at an unprecedented rate and stretching the Secret Service increasingly thin,” said Rep. Elijah Cummings, D-Maryland, the ranking member of the House Oversight and Government Reform Committee.

A Secret Service official provided background information to CBS News indicating that “as a matter of operational security, the Secret Service does not provide information related to the means and methods, or costs associated with our protective operations.”

The Government Accountability Office has begun work on a report that will look at the cost to taxpayers of travel by President Trump’s family.

President Trump’s trips on Air Force One to Mar-a-Lago have cost taxpayers an estimated $700,000 for each round trip. CBS News has estimated, based on a previous Government Accountabilty Office report, that each presidential trip to Mar-a-Lago costs about $3 million.

One purchase order reviewed by CBS News shows the US Secret Service has spent $35,185 on golf cart rentals “for POTUS visit” in Palm Beach County, Florida since the President’s inauguration.

Another purchase order showed a charge of $64,000 for “Elevator services- Trump Tower” in December 2016. A Secret Service official told CBS News that “elevator inspection is one of many protective operational measures utilized by the Secret Service.”